Apparatus for telephone-lines



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E. Tf. GILLILAND. Apparatus for Telephone Lines. No. 236,800. Paientedlan. 18,1881.

UNITED STATES PATENT OFFICE.

EZRA T. GILLILAND, OF CINCINNATI, OHIO, ASSIGNOB. TO AMERICAN BELL TELEPHONE COMPANY, OF BOSTON, MASSACHUSETTS.

SPECIFICATION formingpart of Letters Patent No. 236,800, dated January 18, 1881.

Application filed December 2, 187B.

To all lwhom it 'may concern Beit known that I, EZRA T. GILLILAND, of Cincinnati, in the county of Hamilton and State of Ohio, have invented a new and Improved Apparatus for Telephone-Lines; and I do hereby declare the following to be a full, clear, and exact description of the same, which will enable others skilled in the art to which my invention appertains to make and use it, reference being had to the accompanying drawings, forming part of this specification, in Which- Figure l, Sheet I, is a diagram showing the disposition of my improved apparatus in a telephone-line. Fig. 2, Sheet II, is a perspective view of the signal and switch box with the cover open 5 and Fig. 3, Sheet II, is a similar view of the box with the cover closed.

Similar letters of reference indicate the same parts in the several ligures of the drawings.

Telephone-lin es are generally constructed for business purposes upon what is known as the exchange77 systemthat is to say, a number of lines center at one common office, called an exchange, where there is arranged a series of switches, which, upon a given signal, are so adjusted by an operator as to place any two telephone-lines in communication with each other. The signal apparatus of each line are placed in a closed circuit, and each apparatus is provided with a local switch of some kind, by the operation of which the circuit is opened in the main line and closed with the telephoneline to bring two telephones into circuit for use. Any two telephones of a line may thus' be placed in communication and all the others of a line cut out 5 or, after two lines are connected at the exchange, any telephone of one may be placed in communication with any telephone of thefother line, and all the other telephones of both lines cut out. The intermediate telephone-stations of a line communicate with such line in two directions, one toward the exchange however, through carelessness or inadvertence, that, after the telephones have been used, the operator neglects to throw open the switches of his station, and therefore the main-line circuit remains broken and all the stations cut out excepting those with which he has been having telephonie communication. This, of course, renders the line, as a whole, practically inoperative.

My invention has for its object to overcome this defect and render it impossible for the operator at any station to cut out other telephones of the line after he has ceased to use his own; and to this end it consists in a double switch so arranged as to establish a telephone-circuit either to the right or left of an intermediate station, and so constructed that the telephone or other weight applied to the switch shall automatically disconnect it from either circuit.

The invention has for a further object to improve and simplify the apparatus generally; and in this respect it consists in the construction and combination of various parts, as I will presently describe.

In the accompanying drawings, Fig. l, I have shown a series of telephone-stations, A, placed in a line, whereof B is the battery, preferably located at the exchange. Each station is provided with au electro-magnet, C, an armature, D, connected With the hammer of the call-bell, and two flat springs, E E, electrically connected with opposite poles of the magnet, and with the line-wire F, upon opposite sides of the station, by resting upon the binding posts or plates G.

Gr is a conducting-bar secured in place upon a suitable support at its center with its ends resting above and disconnected from the springs E E.

H is the telephone joined to the bindingposts I I by the requisite wires, one of which, J, is connected with the center of the bar G, and the other with the ground, in the usual manner.

K is the switch made in T form, pivoted to a support immediately under the conductingbar, and preferably formed or otherwise provided with a hook or catch upon its lower end to receive a weigh-t, when required.

The operation of the switch is as follows: If, forexample, an intermediate station desires to communicate with a station upon the right, a suitable signal is given by breaking and IOO closing the main circuit, andthe switch swung up so that its left arm shall pass under the left spring E. This lifts the spring olf its connection with the line-wire and presses it outward against the overlapping end of the connecting-bar, thereby cutting oi communication with the niain line to the left of the station. The operator at the station on the right with which conimnnication is desired, upon receiving the signal, swings the switch of his apparatus to the right to cut off communication in that direction. The two telephones are then in circuit ready for operation, and the stations to the right and left of each circuit cut out. Any two stations may thus be connected by turning the switches to the right or left.

To prevent the switches from being inadvertently left in circuit after using the telephone, the latter is hung upon the hook of the switch, and by its gravity swings the switch out of contact with the springs E. Any other weight than the telephone may be used for the purpose; but 1 prefer to use the telephone, as the switch-hook furnishes a convenient support for it when not in use. A hook or loop, L, should be inserted in the end of the telephone by which to suspend it from the switch-hook; but the wires or other device may be used for the purpose. By means of this gravity-switch the main circuit of the line is automatically closed and the teleplioiie-circiiit cut out from two positions either to the right or left of an intermediate station.

The end stations of a line need not necessarily be provided with the double switch, a single arm on the switch beingr all that is essential, as communication is to be made only' in one direction; but to avoid the expense and inconvenienceofmakingtwokindsofswitches, and to permit the extension of a. line without changing the switch at the end station, I make all the switches double, and they can then be used at any station.

The ends of the switch-head may be beveled, as shown in Fig. 2, for the purpose of passing readily under the ends of the springs E, and the springs should possess sutiicient strength to hold the switch until displaced b v the weight ot' the telephone or other object hung ou the swtch-liook.

The second part of my invention is shown in Figs. 2 and 3, wherein M is the box and N the cover hinged thereto. The whole apparatus is arranged upon the box-cover, and the several wires, excepting thosedirecily attached to the telephone, are connected, through the hinges, with biiidiiig-posts O witiiiii the box, and from these binding-posts extend the line and ground wires. When the box is closed the apparatus is inclosed within it,leaving the shank of the switch projecting through a slot in the bottom, so that it can be easily swung to the right or left. The call-bell P is placed The call-knob R is also upon the outside of the cover and projects through it, so that it can be pushed against one or the other of the springs E for breaking the main circuit to sound the signal. By this arrangement of the instrument it can be locked within the box to prevent it from being tampered with, or it can be exposed for inspection, repairs, &c.; but in either position its connections through the hinges adapt it for operation with the same effect. The box should be secured in any convenient manner to a wall or other suitable support, so as to occupy an upright position, as shown in the drawings.

The double switch may be arranged to open and close a circuit by other means than the springs and connecting-bar, or by a different arrangement thereof than that herein described, withoutdeparting from my invention but I prefer to use these devices as being the most convenient.

Having thus described my invention, what I claim is 1. The double gravity-switch K, combined with the main electric line., the telephone-line, and the signal apparatus, substantially as de scribed, for the purpose speciied.

2. The combination, in a telephone-line with the branches on opposite sides of an intermediate station, of a double switch, substantially as described, operated by the weight of a telephone to disconnect either of said branches, as set forth.

3. The combination of the double switch K with the springs E E of the signal apparatus, substantially as described, for the purpose specitied.

4. The combination of the double switch K with the springs E E and connecting-barG of the signal apparatus, substantially as described, for the purpose specitied.

5. The double switch K, combined with the signal apparatus, the main electric line, and the telephone-line, and adaptedtobeautomatically disconnected from either circuit by weight of a telephone, substantially as described, for the purpose specilied.

6. An automatic switch comprising, in coinbination with line-contact pieces and a conductor for establishing a ground-connection, as required, a shifting telephone-support, as explained, for connecting as desired the line on either side of said contact-pieces with the ground-conductor, and being movable under the weight of the telephone to restore the linecircuit, substantially as set forth.

7. The combination of the switch having the arms, the springs E E, connecting with a local circuit, the plates G', both normally connected with the main circuit, and the spring or a bar connected with a telephone-circuit, substantially as described, for the purpose specied.

E. T. GILLILAND. Witnesses:

E. V. CHERRY, E. A. ELLswo'rH.

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